The present invention relates to a pen holder for holding thereon a pen for drawing a visible line on a board while a sensor generates a signal corresponding to a position of the pen holder on the board.
In an interactive board system as disclosed by JP-A-2000-355188, a position of a pen holder holding therein a pen for drawing a visible line on a board is detected by a sensor arranged on the board to receive a light beam or supersonic waves emitted from the pen holder so that a signal corresponding to the detected position of the pen holder is generated by the sensor to be input to a computer.
An object of the present invention is to provide a pen holder for holding thereon a pen for drawing a visible line on a board while a sensor generates a signal corresponding to a position of the pen holder on the board, a radial size of which pen holder can be minimized while holding stably the pen in the pen holder.
A pen holder for holding thereon a pen for drawing a visible line on a board while a sensor generates a signal corresponding to a position of the pen holder on the board, comprises, an emitter for emitting at least one of light beam and supersonic waves to be detected by the sensor so that the signal is determined from the detected at least one of light beam and supersonic waves, and a holder body including an opening which is arranged at a longitudinal end of the pen holder in such a manner that a front portion of the pen including an end at which end the visible line is drawn on the board projects from the opening out of the pen holder, and through which a part of the pen other than the front portion of the pen is mountable from an outside of the pen holder onto the pen holder so that the pen is held on the pen holder.
Since the part of the pen other than the front portion of the pen is mountable from the outside of the pen holder onto the pen holder through the opening at the longitudinal end of the pen holder, a radial size of the pen holder can be minimized while holding stably the pen in the pen holder.
The pen holder may further comprise a locking member for holding thereon the part of the pen stationarily, the locking member is movable on the holder body between first and second positions, the at least one of light beam and supersonic waves is permitted to be emitted by the emitter when the locking member is positioned at the first position, and the at least one of light beam and supersonic waves is prevented from being emitted by the emitter when the locking member is positioned at the second position.
If the pen has a cap removably mounted on the pen to cover at least the front portion of the pen, and the opening has an inner diameter sufficient for receiving therein a part of the cap so that the part of the cap extends through the opening into the pen holder, the pen holder with the pen covered by the cap can emit effectively the light beam (infrared rays) and/or supersonic waves to be detected by the sensor for generating the signal corresponding to the position of the pen holder on the board on the basis of the detected light beam (infrared rays) and/or supersonic waves.
If the opening has an inner diameter not less than a maximum diameter of the pen, the whole of the pen can be received in the pen holder through the opening. It is preferable that the opening has an inner diameter sufficient for mounting the part of the pen from the outside of the pen holder onto the pen holder through the opening and removing the part of the pen from the pen holder to the outside of the pen holder through the opening.
It is preferable for stably holding the pen in the pen holder that a spring urges the locking member toward the opening so that the pen is urged toward the opening through the locking member.
It is preferable for minimizing the radial size of the pen holder that the locking member has clamping portions whose distance in a direction perpendicular to a longitudinal direction of the pen and the pen holder is elastically changeable so that the part of the pen is held stationarily between the clamping portions with a frictional force between the part of the pen and the clamping portions generated by an elastic clamping force between the clamping portions in the direction perpendicular to the longitudinal direction of the pen.
It is preferable for preventing an excessive axial or longitudinal force from being applied to the pen that the holder body includes a stop portion extending perpendicularly to a movable direction of the locking member on the holder body to engage with the movable locking member so that a movement of the locking member toward the opening is limited by the stop portion when the part of the pen is held on the locking member, so that the holder body is prevented from being pressed against the pen in the movable direction of the locking member to limit through the pen the movement of the locking member toward the opening.
The locking member is positioned at the first position when the pen holder is urged toward the board so that the end of the pen is pressed against the board, and the locking member is positioned at the second position when the pen holder is prevented from being urged toward the board so that the end of the pen is separated away from the board.
If the locking member extends circumferentially so that, as seen in a longitudinal direction of the pen and the pen holder, the pen is substantially surrounded by the locking member to restrain a movement of the pen with respect to the locking member in each of radial directions perpendicular to each other, the pen is stably held in the locking member.